/***
 * ASM XML Adapter
 * Copyright (c) 2004-2011, Eugene Kuleshov
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.sinosoft.monitor.org.objectweb.asm.xml;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.sinosoft.monitor.org.objectweb.asm.AnnotationVisitor;
import com.sinosoft.monitor.org.objectweb.asm.ClassVisitor;
import com.sinosoft.monitor.org.objectweb.asm.FieldVisitor;
import com.sinosoft.monitor.org.objectweb.asm.Handle;
import com.sinosoft.monitor.org.objectweb.asm.Label;
import com.sinosoft.monitor.org.objectweb.asm.MethodVisitor;
import com.sinosoft.monitor.org.objectweb.asm.Opcodes;
import com.sinosoft.monitor.org.objectweb.asm.Type;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * A {@link org.xml.sax.ContentHandler ContentHandler} that transforms XML
 * document into Java class file. This class can be feeded by any kind of SAX
 * 2.0 event producers, e.g. XML parser, XSLT or XPath engines, or custom code.
 *
 * @author Eugene Kuleshov
 * @see SAXClassAdapter
 * @see Processor
 */
public class ASMContentHandler extends DefaultHandler implements Opcodes {

	/**
	 * Stack of the intermediate processing contexts.
	 */
	private final ArrayList<Object> stack = new ArrayList<Object>();

	/**
	 * Complete name of the current element.
	 */
	String match = "";

	/**
	 * Current instance of the {@link ClassVisitor ClassVisitor} used to visit
	 * classfile bytecode.
	 */
	protected ClassVisitor cv;

	/**
	 * Map of the active {@link Label Label} instances for current method.
	 */
	protected Map<Object, Label> labels;

	private static final String BASE = "class";

	private final RuleSet RULES = new RuleSet();

	{
		RULES.add(BASE, new ClassRule());
		RULES.add(BASE + "/interfaces/interface", new InterfaceRule());
		RULES.add(BASE + "/interfaces", new InterfacesRule());
		RULES.add(BASE + "/outerclass", new OuterClassRule());
		RULES.add(BASE + "/innerclass", new InnerClassRule());
		RULES.add(BASE + "/source", new SourceRule());
		RULES.add(BASE + "/field", new FieldRule());

		RULES.add(BASE + "/method", new MethodRule());
		RULES.add(BASE + "/method/exceptions/exception", new ExceptionRule());
		RULES.add(BASE + "/method/exceptions", new ExceptionsRule());

		RULES.add(BASE + "/method/annotationDefault",
				new AnnotationDefaultRule());

		RULES.add(BASE + "/method/code/*", new OpcodesRule()); // opcodes

		RULES.add(BASE + "/method/code/frame", new FrameRule());
		RULES.add(BASE + "/method/code/frame/local", new FrameTypeRule());
		RULES.add(BASE + "/method/code/frame/stack", new FrameTypeRule());

		RULES.add(BASE + "/method/code/TABLESWITCH", new TableSwitchRule());
		RULES.add(BASE + "/method/code/TABLESWITCH/label",
				new TableSwitchLabelRule());
		RULES.add(BASE + "/method/code/LOOKUPSWITCH", new LookupSwitchRule());
		RULES.add(BASE + "/method/code/LOOKUPSWITCH/label",
				new LookupSwitchLabelRule());

		RULES.add(BASE + "/method/code/INVOKEDYNAMIC", new InvokeDynamicRule());
		RULES.add(BASE + "/method/code/INVOKEDYNAMIC/bsmArg",
				new InvokeDynamicBsmArgumentsRule());

		RULES.add(BASE + "/method/code/Label", new LabelRule());
		RULES.add(BASE + "/method/code/TryCatch", new TryCatchRule());
		RULES.add(BASE + "/method/code/LineNumber", new LineNumberRule());
		RULES.add(BASE + "/method/code/LocalVar", new LocalVarRule());
		RULES.add(BASE + "/method/code/Max", new MaxRule());

		RULES.add("*/annotation", new AnnotationRule());
		RULES.add("*/parameterAnnotation", new AnnotationParameterRule());
		RULES.add("*/annotationValue", new AnnotationValueRule());
		RULES.add("*/annotationValueAnnotation",
				new AnnotationValueAnnotationRule());
		RULES.add("*/annotationValueEnum", new AnnotationValueEnumRule());
		RULES.add("*/annotationValueArray", new AnnotationValueArrayRule());
	}

	private static interface OpcodeGroup {
		public static final int INSN = 0;
		public static final int INSN_INT = 1;
		public static final int INSN_VAR = 2;
		public static final int INSN_TYPE = 3;
		public static final int INSN_FIELD = 4;
		public static final int INSN_METHOD = 5;
		public static final int INSN_JUMP = 6;
		public static final int INSN_LDC = 7;
		public static final int INSN_IINC = 8;
		public static final int INSN_MULTIANEWARRAY = 9;
	}

	/**
	 * Map of the opcode names to opcode and opcode group
	 */
	static final HashMap<String, Opcode> OPCODES = new HashMap<String, Opcode>();

	static {
		addOpcode("NOP", NOP, OpcodeGroup.INSN);
		addOpcode("ACONST_NULL", ACONST_NULL, OpcodeGroup.INSN);
		addOpcode("ICONST_M1", ICONST_M1, OpcodeGroup.INSN);
		addOpcode("ICONST_0", ICONST_0, OpcodeGroup.INSN);
		addOpcode("ICONST_1", ICONST_1, OpcodeGroup.INSN);
		addOpcode("ICONST_2", ICONST_2, OpcodeGroup.INSN);
		addOpcode("ICONST_3", ICONST_3, OpcodeGroup.INSN);
		addOpcode("ICONST_4", ICONST_4, OpcodeGroup.INSN);
		addOpcode("ICONST_5", ICONST_5, OpcodeGroup.INSN);
		addOpcode("LCONST_0", LCONST_0, OpcodeGroup.INSN);
		addOpcode("LCONST_1", LCONST_1, OpcodeGroup.INSN);
		addOpcode("FCONST_0", FCONST_0, OpcodeGroup.INSN);
		addOpcode("FCONST_1", FCONST_1, OpcodeGroup.INSN);
		addOpcode("FCONST_2", FCONST_2, OpcodeGroup.INSN);
		addOpcode("DCONST_0", DCONST_0, OpcodeGroup.INSN);
		addOpcode("DCONST_1", DCONST_1, OpcodeGroup.INSN);
		addOpcode("BIPUSH", BIPUSH, OpcodeGroup.INSN_INT);
		addOpcode("SIPUSH", SIPUSH, OpcodeGroup.INSN_INT);
		addOpcode("LDC", LDC, OpcodeGroup.INSN_LDC);
		addOpcode("ILOAD", ILOAD, OpcodeGroup.INSN_VAR);
		addOpcode("LLOAD", LLOAD, OpcodeGroup.INSN_VAR);
		addOpcode("FLOAD", FLOAD, OpcodeGroup.INSN_VAR);
		addOpcode("DLOAD", DLOAD, OpcodeGroup.INSN_VAR);
		addOpcode("ALOAD", ALOAD, OpcodeGroup.INSN_VAR);
		addOpcode("IALOAD", IALOAD, OpcodeGroup.INSN);
		addOpcode("LALOAD", LALOAD, OpcodeGroup.INSN);
		addOpcode("FALOAD", FALOAD, OpcodeGroup.INSN);
		addOpcode("DALOAD", DALOAD, OpcodeGroup.INSN);
		addOpcode("AALOAD", AALOAD, OpcodeGroup.INSN);
		addOpcode("BALOAD", BALOAD, OpcodeGroup.INSN);
		addOpcode("CALOAD", CALOAD, OpcodeGroup.INSN);
		addOpcode("SALOAD", SALOAD, OpcodeGroup.INSN);
		addOpcode("ISTORE", ISTORE, OpcodeGroup.INSN_VAR);
		addOpcode("LSTORE", LSTORE, OpcodeGroup.INSN_VAR);
		addOpcode("FSTORE", FSTORE, OpcodeGroup.INSN_VAR);
		addOpcode("DSTORE", DSTORE, OpcodeGroup.INSN_VAR);
		addOpcode("ASTORE", ASTORE, OpcodeGroup.INSN_VAR);
		addOpcode("IASTORE", IASTORE, OpcodeGroup.INSN);
		addOpcode("LASTORE", LASTORE, OpcodeGroup.INSN);
		addOpcode("FASTORE", FASTORE, OpcodeGroup.INSN);
		addOpcode("DASTORE", DASTORE, OpcodeGroup.INSN);
		addOpcode("AASTORE", AASTORE, OpcodeGroup.INSN);
		addOpcode("BASTORE", BASTORE, OpcodeGroup.INSN);
		addOpcode("CASTORE", CASTORE, OpcodeGroup.INSN);
		addOpcode("SASTORE", SASTORE, OpcodeGroup.INSN);
		addOpcode("POP", POP, OpcodeGroup.INSN);
		addOpcode("POP2", POP2, OpcodeGroup.INSN);
		addOpcode("DUP", DUP, OpcodeGroup.INSN);
		addOpcode("DUP_X1", DUP_X1, OpcodeGroup.INSN);
		addOpcode("DUP_X2", DUP_X2, OpcodeGroup.INSN);
		addOpcode("DUP2", DUP2, OpcodeGroup.INSN);
		addOpcode("DUP2_X1", DUP2_X1, OpcodeGroup.INSN);
		addOpcode("DUP2_X2", DUP2_X2, OpcodeGroup.INSN);
		addOpcode("SWAP", SWAP, OpcodeGroup.INSN);
		addOpcode("IADD", IADD, OpcodeGroup.INSN);
		addOpcode("LADD", LADD, OpcodeGroup.INSN);
		addOpcode("FADD", FADD, OpcodeGroup.INSN);
		addOpcode("DADD", DADD, OpcodeGroup.INSN);
		addOpcode("ISUB", ISUB, OpcodeGroup.INSN);
		addOpcode("LSUB", LSUB, OpcodeGroup.INSN);
		addOpcode("FSUB", FSUB, OpcodeGroup.INSN);
		addOpcode("DSUB", DSUB, OpcodeGroup.INSN);
		addOpcode("IMUL", IMUL, OpcodeGroup.INSN);
		addOpcode("LMUL", LMUL, OpcodeGroup.INSN);
		addOpcode("FMUL", FMUL, OpcodeGroup.INSN);
		addOpcode("DMUL", DMUL, OpcodeGroup.INSN);
		addOpcode("IDIV", IDIV, OpcodeGroup.INSN);
		addOpcode("LDIV", LDIV, OpcodeGroup.INSN);
		addOpcode("FDIV", FDIV, OpcodeGroup.INSN);
		addOpcode("DDIV", DDIV, OpcodeGroup.INSN);
		addOpcode("IREM", IREM, OpcodeGroup.INSN);
		addOpcode("LREM", LREM, OpcodeGroup.INSN);
		addOpcode("FREM", FREM, OpcodeGroup.INSN);
		addOpcode("DREM", DREM, OpcodeGroup.INSN);
		addOpcode("INEG", INEG, OpcodeGroup.INSN);
		addOpcode("LNEG", LNEG, OpcodeGroup.INSN);
		addOpcode("FNEG", FNEG, OpcodeGroup.INSN);
		addOpcode("DNEG", DNEG, OpcodeGroup.INSN);
		addOpcode("ISHL", ISHL, OpcodeGroup.INSN);
		addOpcode("LSHL", LSHL, OpcodeGroup.INSN);
		addOpcode("ISHR", ISHR, OpcodeGroup.INSN);
		addOpcode("LSHR", LSHR, OpcodeGroup.INSN);
		addOpcode("IUSHR", IUSHR, OpcodeGroup.INSN);
		addOpcode("LUSHR", LUSHR, OpcodeGroup.INSN);
		addOpcode("IAND", IAND, OpcodeGroup.INSN);
		addOpcode("LAND", LAND, OpcodeGroup.INSN);
		addOpcode("IOR", IOR, OpcodeGroup.INSN);
		addOpcode("LOR", LOR, OpcodeGroup.INSN);
		addOpcode("IXOR", IXOR, OpcodeGroup.INSN);
		addOpcode("LXOR", LXOR, OpcodeGroup.INSN);
		addOpcode("IINC", IINC, OpcodeGroup.INSN_IINC);
		addOpcode("I2L", I2L, OpcodeGroup.INSN);
		addOpcode("I2F", I2F, OpcodeGroup.INSN);
		addOpcode("I2D", I2D, OpcodeGroup.INSN);
		addOpcode("L2I", L2I, OpcodeGroup.INSN);
		addOpcode("L2F", L2F, OpcodeGroup.INSN);
		addOpcode("L2D", L2D, OpcodeGroup.INSN);
		addOpcode("F2I", F2I, OpcodeGroup.INSN);
		addOpcode("F2L", F2L, OpcodeGroup.INSN);
		addOpcode("F2D", F2D, OpcodeGroup.INSN);
		addOpcode("D2I", D2I, OpcodeGroup.INSN);
		addOpcode("D2L", D2L, OpcodeGroup.INSN);
		addOpcode("D2F", D2F, OpcodeGroup.INSN);
		addOpcode("I2B", I2B, OpcodeGroup.INSN);
		addOpcode("I2C", I2C, OpcodeGroup.INSN);
		addOpcode("I2S", I2S, OpcodeGroup.INSN);
		addOpcode("LCMP", LCMP, OpcodeGroup.INSN);
		addOpcode("FCMPL", FCMPL, OpcodeGroup.INSN);
		addOpcode("FCMPG", FCMPG, OpcodeGroup.INSN);
		addOpcode("DCMPL", DCMPL, OpcodeGroup.INSN);
		addOpcode("DCMPG", DCMPG, OpcodeGroup.INSN);
		addOpcode("IFEQ", IFEQ, OpcodeGroup.INSN_JUMP);
		addOpcode("IFNE", IFNE, OpcodeGroup.INSN_JUMP);
		addOpcode("IFLT", IFLT, OpcodeGroup.INSN_JUMP);
		addOpcode("IFGE", IFGE, OpcodeGroup.INSN_JUMP);
		addOpcode("IFGT", IFGT, OpcodeGroup.INSN_JUMP);
		addOpcode("IFLE", IFLE, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPEQ", IF_ICMPEQ, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPNE", IF_ICMPNE, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPLT", IF_ICMPLT, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPGE", IF_ICMPGE, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPGT", IF_ICMPGT, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ICMPLE", IF_ICMPLE, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ACMPEQ", IF_ACMPEQ, OpcodeGroup.INSN_JUMP);
		addOpcode("IF_ACMPNE", IF_ACMPNE, OpcodeGroup.INSN_JUMP);
		addOpcode("GOTO", GOTO, OpcodeGroup.INSN_JUMP);
		addOpcode("JSR", JSR, OpcodeGroup.INSN_JUMP);
		addOpcode("RET", RET, OpcodeGroup.INSN_VAR);
		addOpcode("IRETURN", IRETURN, OpcodeGroup.INSN);
		addOpcode("LRETURN", LRETURN, OpcodeGroup.INSN);
		addOpcode("FRETURN", FRETURN, OpcodeGroup.INSN);
		addOpcode("DRETURN", DRETURN, OpcodeGroup.INSN);
		addOpcode("ARETURN", ARETURN, OpcodeGroup.INSN);
		addOpcode("RETURN", RETURN, OpcodeGroup.INSN);
		addOpcode("GETSTATIC", GETSTATIC, OpcodeGroup.INSN_FIELD);
		addOpcode("PUTSTATIC", PUTSTATIC, OpcodeGroup.INSN_FIELD);
		addOpcode("GETFIELD", GETFIELD, OpcodeGroup.INSN_FIELD);
		addOpcode("PUTFIELD", PUTFIELD, OpcodeGroup.INSN_FIELD);
		addOpcode("INVOKEVIRTUAL", INVOKEVIRTUAL, OpcodeGroup.INSN_METHOD);
		addOpcode("INVOKESPECIAL", INVOKESPECIAL, OpcodeGroup.INSN_METHOD);
		addOpcode("INVOKESTATIC", INVOKESTATIC, OpcodeGroup.INSN_METHOD);
		addOpcode("INVOKEINTERFACE", INVOKEINTERFACE, OpcodeGroup.INSN_METHOD);
		addOpcode("NEW", NEW, OpcodeGroup.INSN_TYPE);
		addOpcode("NEWARRAY", NEWARRAY, OpcodeGroup.INSN_INT);
		addOpcode("ANEWARRAY", ANEWARRAY, OpcodeGroup.INSN_TYPE);
		addOpcode("ARRAYLENGTH", ARRAYLENGTH, OpcodeGroup.INSN);
		addOpcode("ATHROW", ATHROW, OpcodeGroup.INSN);
		addOpcode("CHECKCAST", CHECKCAST, OpcodeGroup.INSN_TYPE);
		addOpcode("INSTANCEOF", INSTANCEOF, OpcodeGroup.INSN_TYPE);
		addOpcode("MONITORENTER", MONITORENTER, OpcodeGroup.INSN);
		addOpcode("MONITOREXIT", MONITOREXIT, OpcodeGroup.INSN);
		addOpcode("MULTIANEWARRAY", MULTIANEWARRAY,
				OpcodeGroup.INSN_MULTIANEWARRAY);
		addOpcode("IFNULL", IFNULL, OpcodeGroup.INSN_JUMP);
		addOpcode("IFNONNULL", IFNONNULL, OpcodeGroup.INSN_JUMP);
	}

	private static void addOpcode(String operStr, int oper, int group) {
		OPCODES.put(operStr, new Opcode(oper, group));
	}

	static final HashMap<String, Integer> TYPES = new HashMap<String, Integer>();

	static {
		String[] types = SAXCodeAdapter.TYPES;
		for (int i = 0; i < types.length; i++) {
			TYPES.put(types[i], new Integer(i));
		}
	}

	/**
	 * Constructs a new {@link com.sinosoft.monitor.com.sinosoft.monitor.org.objectweb.asm.xml.ASMContentHandler ASMContentHandler} object.
	 *
	 * @param cv class visitor that will be called to reconstruct the classfile
	 *           using the XML stream.
	 */
	public ASMContentHandler(final ClassVisitor cv) {
		this.cv = cv;
	}

	/**
	 * Process notification of the start of an XML element being reached.
	 *
	 * @param ns    - The Namespace URI, or the empty string if the element has no
	 *              Namespace URI or if Namespace processing is not being
	 *              performed.
	 * @param lName - The local name (without prefix), or the empty string if
	 *              Namespace processing is not being performed.
	 * @param qName - The qualified name (with prefix), or the empty string if
	 *              qualified names are not available.
	 * @param list  - The attributes attached to the element. If there are no
	 *              attributes, it shall be an empty Attributes object.
	 * @throws org.xml.sax.SAXException if a parsing error is to be reported
	 */
	@Override
	public final void startElement(final String ns, final String lName,
	                               final String qName, final Attributes list) throws SAXException {
		// the actual element name is either in lName or qName, depending
		// on whether the parser is namespace aware
		String name = lName == null || lName.length() == 0 ? qName : lName;

		// Compute the current matching rule
		StringBuffer sb = new StringBuffer(match);
		if (match.length() > 0) {
			sb.append('/');
		}
		sb.append(name);
		match = sb.toString();

		// Fire "begin" events for all relevant rules
		Rule r = (Rule) RULES.match(match);
		if (r != null) {
			r.begin(name, list);
		}
	}

	/**
	 * Process notification of the end of an XML element being reached.
	 *
	 * @param ns    - The Namespace URI, or the empty string if the element has no
	 *              Namespace URI or if Namespace processing is not being
	 *              performed.
	 * @param lName - The local name (without prefix), or the empty string if
	 *              Namespace processing is not being performed.
	 * @param qName - The qualified XML 1.0 name (with prefix), or the empty
	 *              string if qualified names are not available.
	 * @throws org.xml.sax.SAXException if a parsing error is to be reported
	 */
	@Override
	public final void endElement(final String ns, final String lName,
	                             final String qName) throws SAXException {
		// the actual element name is either in lName or qName, depending
		// on whether the parser is namespace aware
		String name = lName == null || lName.length() == 0 ? qName : lName;

		// Fire "end" events for all relevant rules in reverse order
		Rule r = (Rule) RULES.match(match);
		if (r != null) {
			r.end(name);
		}

		// Recover the previous match expression
		int slash = match.lastIndexOf('/');
		if (slash >= 0) {
			match = match.substring(0, slash);
		} else {
			match = "";
		}
	}

	/**
	 * Return the top object on the stack without removing it. If there are no
	 * objects on the stack, return <code>null</code>.
	 *
	 * @return the top object on the stack without removing it.
	 */
	final Object peek() {
		int size = stack.size();
		return size == 0 ? null : stack.get(size - 1);
	}

	/**
	 * Pop the top object off of the stack, and return it. If there are no
	 * objects on the stack, return <code>null</code>.
	 *
	 * @return the top object off of the stack.
	 */
	final Object pop() {
		int size = stack.size();
		return size == 0 ? null : stack.remove(size - 1);
	}

	/**
	 * Push a new object onto the top of the object stack.
	 *
	 * @param object The new object
	 */
	final void push(final Object object) {
		stack.add(object);
	}

	static final class RuleSet {

		private final HashMap<String, Object> rules = new HashMap<String, Object>();

		private final ArrayList<String> lpatterns = new ArrayList<String>();

		private final ArrayList<String> rpatterns = new ArrayList<String>();

		public void add(final String path, final Object rule) {
			String pattern = path;
			if (path.startsWith("*/")) {
				pattern = path.substring(1);
				lpatterns.add(pattern);
			} else if (path.endsWith("/*")) {
				pattern = path.substring(0, path.length() - 1);
				rpatterns.add(pattern);
			}
			rules.put(pattern, rule);
		}

		public Object match(final String path) {
			if (rules.containsKey(path)) {
				return rules.get(path);
			}

			int n = path.lastIndexOf('/');
			for (Iterator<String> it = lpatterns.iterator(); it.hasNext(); ) {
				String pattern = it.next();
				if (path.substring(n).endsWith(pattern)) {
					return rules.get(pattern);
				}
			}

			for (Iterator<String> it = rpatterns.iterator(); it.hasNext(); ) {
				String pattern = it.next();
				if (path.startsWith(pattern)) {
					return rules.get(pattern);
				}
			}

			return null;
		}
	}

	/**
	 * Rule
	 */
	protected abstract class Rule {

		public void begin(final String name, final Attributes attrs)
				throws SAXException {
		}

		public void end(final String name) {
		}

		protected final Object getValue(final String desc, final String val)
				throws SAXException {
			Object value = null;
			if (val != null) {
				if ("Ljava/lang/String;".equals(desc)) {
					value = decode(val);
				} else if ("Ljava/lang/Integer;".equals(desc)
						|| "I".equals(desc) || "S".equals(desc)
						|| "B".equals(desc) || "C".equals(desc)
						|| "Z".equals(desc)) {
					value = new Integer(val);

				} else if ("Ljava/lang/Short;".equals(desc)) {
					value = new Short(val);

				} else if ("Ljava/lang/Byte;".equals(desc)) {
					value = new Byte(val);

				} else if ("Ljava/lang/Character;".equals(desc)) {
					value = new Character(decode(val).charAt(0));

				} else if ("Ljava/lang/Boolean;".equals(desc)) {
					value = Boolean.valueOf(val);

				} else if ("Ljava/lang/Long;".equals(desc) || "J".equals(desc)) {
					value = new Long(val);
				} else if ("Ljava/lang/Float;".equals(desc) || "F".equals(desc)) {
					value = new Float(val);
				} else if ("Ljava/lang/Double;".equals(desc)
						|| "D".equals(desc)) {
					value = new Double(val);
				} else if (Type.getDescriptor(Type.class).equals(desc)) {
					value = Type.getType(val);

				} else if (Type.getDescriptor(Handle.class).equals(desc)) {
					value = decodeHandle(val);

				} else {
					// TODO use of default toString().
					throw new SAXException("Invalid value:" + val + " desc:"
							+ desc + " ctx:" + this);
				}
			}
			return value;
		}

		Handle decodeHandle(final String val) throws SAXException {
			try {
				int dotIndex = val.indexOf('.');
				int descIndex = val.indexOf('(', dotIndex + 1);
				int tagIndex = val.lastIndexOf('(');

				int tag = Integer.parseInt(val.substring(tagIndex + 1,
						val.length() - 1));
				String owner = val.substring(0, dotIndex);
				String name = val.substring(dotIndex + 1, descIndex);
				String desc = val.substring(descIndex, tagIndex - 1);
				return new Handle(tag, owner, name, desc);

			} catch (RuntimeException e) {
				throw new SAXException("Malformed handle " + val, e);
			}
		}

		private final String decode(final String val) throws SAXException {
			StringBuffer sb = new StringBuffer(val.length());
			try {
				int n = 0;
				while (n < val.length()) {
					char c = val.charAt(n);
					if (c == '\\') {
						n++;
						c = val.charAt(n);
						if (c == '\\') {
							sb.append('\\');
						} else {
							n++; // skip 'u'
							sb.append((char) Integer.parseInt(
									val.substring(n, n + 4), 16));
							n += 3;
						}
					} else {
						sb.append(c);
					}
					n++;
				}

			} catch (RuntimeException ex) {
				throw new SAXException(ex);
			}
			return sb.toString();
		}

		protected final Label getLabel(final Object label) {
			Label lbl = labels.get(label);
			if (lbl == null) {
				lbl = new Label();
				labels.put(label, lbl);
			}
			return lbl;
		}

		// TODO verify move to stack
		protected final MethodVisitor getCodeVisitor() {
			return (MethodVisitor) peek();
		}

		protected final int getAccess(final String s) {
			int access = 0;
			if (s.indexOf("public") != -1) {
				access |= ACC_PUBLIC;
			}
			if (s.indexOf("private") != -1) {
				access |= ACC_PRIVATE;
			}
			if (s.indexOf("protected") != -1) {
				access |= ACC_PROTECTED;
			}
			if (s.indexOf("static") != -1) {
				access |= ACC_STATIC;
			}
			if (s.indexOf("final") != -1) {
				access |= ACC_FINAL;
			}
			if (s.indexOf("super") != -1) {
				access |= ACC_SUPER;
			}
			if (s.indexOf("synchronized") != -1) {
				access |= ACC_SYNCHRONIZED;
			}
			if (s.indexOf("volatile") != -1) {
				access |= ACC_VOLATILE;
			}
			if (s.indexOf("bridge") != -1) {
				access |= ACC_BRIDGE;
			}
			if (s.indexOf("varargs") != -1) {
				access |= ACC_VARARGS;
			}
			if (s.indexOf("transient") != -1) {
				access |= ACC_TRANSIENT;
			}
			if (s.indexOf("native") != -1) {
				access |= ACC_NATIVE;
			}
			if (s.indexOf("interface") != -1) {
				access |= ACC_INTERFACE;
			}
			if (s.indexOf("abstract") != -1) {
				access |= ACC_ABSTRACT;
			}
			if (s.indexOf("strict") != -1) {
				access |= ACC_STRICT;
			}
			if (s.indexOf("synthetic") != -1) {
				access |= ACC_SYNTHETIC;
			}
			if (s.indexOf("annotation") != -1) {
				access |= ACC_ANNOTATION;
			}
			if (s.indexOf("enum") != -1) {
				access |= ACC_ENUM;
			}
			if (s.indexOf("deprecated") != -1) {
				access |= ACC_DEPRECATED;
			}
			return access;
		}
	}

	/**
	 * ClassRule
	 */
	final class ClassRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			int major = Integer.parseInt(attrs.getValue("major"));
			int minor = Integer.parseInt(attrs.getValue("minor"));
			HashMap<String, Object> vals = new HashMap<String, Object>();
			vals.put("version", new Integer(minor << 16 | major));
			vals.put("access", attrs.getValue("access"));
			vals.put("name", attrs.getValue("name"));
			vals.put("parent", attrs.getValue("parent"));
			vals.put("source", attrs.getValue("source"));
			vals.put("signature", attrs.getValue("signature"));
			vals.put("interfaces", new ArrayList<String>());
			push(vals);
			// values will be extracted in InterfacesRule.end();
		}
	}

	final class SourceRule extends Rule {

		@Override
		public void begin(final String name, final Attributes attrs) {
			String file = attrs.getValue("file");
			String debug = attrs.getValue("debug");
			cv.visitSource(file, debug);
		}
	}

	/**
	 * InterfaceRule
	 */
	final class InterfaceRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			((ArrayList<String>) ((HashMap<?, ?>) peek()).get("interfaces"))
					.add(attrs.getValue("name"));
		}
	}

	/**
	 * InterfacesRule
	 */
	final class InterfacesRule extends Rule {

		@Override
		public final void end(final String element) {
			HashMap<?, ?> vals = (HashMap<?, ?>) pop();
			int version = ((Integer) vals.get("version")).intValue();
			int access = getAccess((String) vals.get("access"));
			String name = (String) vals.get("name");
			String signature = (String) vals.get("signature");
			String parent = (String) vals.get("parent");
			ArrayList<?> infs = (ArrayList<?>) vals.get("interfaces");
			String[] interfaces = infs.toArray(new String[infs.size()]);
			cv.visit(version, access, name, signature, parent, interfaces);
			push(cv);
		}
	}

	/**
	 * OuterClassRule
	 */
	final class OuterClassRule extends Rule {

		@Override
		public final void begin(final String element, final Attributes attrs) {
			String owner = attrs.getValue("owner");
			String name = attrs.getValue("name");
			String desc = attrs.getValue("desc");
			cv.visitOuterClass(owner, name, desc);
		}
	}

	/**
	 * InnerClassRule
	 */
	final class InnerClassRule extends Rule {

		@Override
		public final void begin(final String element, final Attributes attrs) {
			int access = getAccess(attrs.getValue("access"));
			String name = attrs.getValue("name");
			String outerName = attrs.getValue("outerName");
			String innerName = attrs.getValue("innerName");
			cv.visitInnerClass(name, outerName, innerName, access);
		}
	}

	/**
	 * FieldRule
	 */
	final class FieldRule extends Rule {

		@Override
		public final void begin(final String element, final Attributes attrs)
				throws SAXException {
			int access = getAccess(attrs.getValue("access"));
			String name = attrs.getValue("name");
			String signature = attrs.getValue("signature");
			String desc = attrs.getValue("desc");
			Object value = getValue(desc, attrs.getValue("value"));
			push(cv.visitField(access, name, desc, signature, value));
		}

		@Override
		public void end(final String name) {
			((FieldVisitor) pop()).visitEnd();
		}
	}

	/**
	 * MethodRule
	 */
	final class MethodRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			labels = new HashMap<Object, Label>();
			HashMap<String, Object> vals = new HashMap<String, Object>();
			vals.put("access", attrs.getValue("access"));
			vals.put("name", attrs.getValue("name"));
			vals.put("desc", attrs.getValue("desc"));
			vals.put("signature", attrs.getValue("signature"));
			vals.put("exceptions", new ArrayList<String>());
			push(vals);
			// values will be extracted in ExceptionsRule.end();
		}

		@Override
		public final void end(final String name) {
			((MethodVisitor) pop()).visitEnd();
			labels = null;
		}
	}

	/**
	 * ExceptionRule
	 */
	final class ExceptionRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			((ArrayList<String>) ((HashMap<?, ?>) peek()).get("exceptions"))
					.add(attrs.getValue("name"));
		}
	}

	/**
	 * ExceptionsRule
	 */
	final class ExceptionsRule extends Rule {

		@Override
		public final void end(final String element) {
			HashMap<?, ?> vals = (HashMap<?, ?>) pop();
			int access = getAccess((String) vals.get("access"));
			String name = (String) vals.get("name");
			String desc = (String) vals.get("desc");
			String signature = (String) vals.get("signature");
			ArrayList<?> excs = (ArrayList<?>) vals.get("exceptions");
			String[] exceptions = excs.toArray(new String[excs.size()]);

			push(cv.visitMethod(access, name, desc, signature, exceptions));
		}
	}

	/**
	 * TableSwitchRule
	 */
	final class TableSwitchRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			HashMap<String, Object> vals = new HashMap<String, Object>();
			vals.put("min", attrs.getValue("min"));
			vals.put("max", attrs.getValue("max"));
			vals.put("dflt", attrs.getValue("dflt"));
			vals.put("labels", new ArrayList<String>());
			push(vals);
		}

		@Override
		public final void end(final String name) {
			HashMap<?, ?> vals = (HashMap<?, ?>) pop();
			int min = Integer.parseInt((String) vals.get("min"));
			int max = Integer.parseInt((String) vals.get("max"));
			Label dflt = getLabel(vals.get("dflt"));
			ArrayList<?> lbls = (ArrayList<?>) vals.get("labels");
			Label[] labels = lbls.toArray(new Label[lbls.size()]);
			getCodeVisitor().visitTableSwitchInsn(min, max, dflt, labels);
		}
	}

	/**
	 * TableSwitchLabelRule
	 */
	final class TableSwitchLabelRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			((ArrayList<Label>) ((HashMap<?, ?>) peek()).get("labels"))
					.add(getLabel(attrs.getValue("name")));
		}
	}

	/**
	 * LookupSwitchRule
	 */
	final class LookupSwitchRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			HashMap<String, Object> vals = new HashMap<String, Object>();
			vals.put("dflt", attrs.getValue("dflt"));
			vals.put("labels", new ArrayList<Label>());
			vals.put("keys", new ArrayList<String>());
			push(vals);
		}

		@Override
		public final void end(final String name) {
			HashMap<?, ?> vals = (HashMap<?, ?>) pop();
			Label dflt = getLabel(vals.get("dflt"));
			ArrayList<String> keyList = (ArrayList<String>) vals.get("keys");
			ArrayList<?> lbls = (ArrayList<?>) vals.get("labels");
			Label[] labels = lbls.toArray(new Label[lbls.size()]);
			int[] keys = new int[keyList.size()];
			for (int i = 0; i < keys.length; i++) {
				keys[i] = Integer.parseInt(keyList.get(i));
			}
			getCodeVisitor().visitLookupSwitchInsn(dflt, keys, labels);
		}
	}

	/**
	 * LookupSwitchLabelRule
	 */
	final class LookupSwitchLabelRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			HashMap<?, ?> vals = (HashMap<?, ?>) peek();
			((ArrayList<Label>) vals.get("labels")).add(getLabel(attrs
					.getValue("name")));
			((ArrayList<String>) vals.get("keys")).add(attrs.getValue("key"));
		}
	}

	/**
	 * FrameRule
	 */
	final class FrameRule extends Rule {

		@Override
		public void begin(final String name, final Attributes attrs) {
			HashMap<String, Object> typeLists = new HashMap<String, Object>();
			typeLists.put("local", new ArrayList<Object>());
			typeLists.put("stack", new ArrayList<Object>());
			push(attrs.getValue("type"));
			push(attrs.getValue("count") == null ? "0" : attrs
					.getValue("count"));
			push(typeLists);
		}

		@Override
		public void end(final String name) {
			HashMap<?, ?> typeLists = (HashMap<?, ?>) pop();
			ArrayList<?> locals = (ArrayList<?>) typeLists.get("local");
			int nLocal = locals.size();
			Object[] local = locals.toArray();
			ArrayList<?> stacks = (ArrayList<?>) typeLists.get("stack");
			int nStack = stacks.size();
			Object[] stack = stacks.toArray();
			String count = (String) pop();
			String type = (String) pop();
			if ("NEW".equals(type)) {
				getCodeVisitor()
						.visitFrame(F_NEW, nLocal, local, nStack, stack);
			} else if ("FULL".equals(type)) {
				getCodeVisitor().visitFrame(F_FULL, nLocal, local, nStack,
						stack);
			} else if ("APPEND".equals(type)) {
				getCodeVisitor().visitFrame(F_APPEND, nLocal, local, 0, null);
			} else if ("CHOP".equals(type)) {
				getCodeVisitor().visitFrame(F_CHOP, Integer.parseInt(count),
						null, 0, null);
			} else if ("SAME".equals(type)) {
				getCodeVisitor().visitFrame(F_SAME, 0, null, 0, null);
			} else if ("SAME1".equals(type)) {
				getCodeVisitor().visitFrame(F_SAME1, 0, null, nStack, stack);
			}
		}
	}

	final class FrameTypeRule extends Rule {

		@Override
		public void begin(final String name, final Attributes attrs) {
			ArrayList<Object> types = (ArrayList<Object>) ((HashMap<?, ?>) peek())
					.get(name);
			String type = attrs.getValue("type");
			if ("uninitialized".equals(type)) {
				types.add(getLabel(attrs.getValue("label")));
			} else {
				Integer t = TYPES.get(type);
				if (t == null) {
					types.add(type);
				} else {
					types.add(t);
				}
			}
		}
	}

	/**
	 * LabelRule
	 */
	final class LabelRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			getCodeVisitor().visitLabel(getLabel(attrs.getValue("name")));
		}
	}

	/**
	 * TryCatchRule
	 */
	final class TryCatchRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			Label start = getLabel(attrs.getValue("start"));
			Label end = getLabel(attrs.getValue("end"));
			Label handler = getLabel(attrs.getValue("handler"));
			String type = attrs.getValue("type");
			getCodeVisitor().visitTryCatchBlock(start, end, handler, type);
		}
	}

	/**
	 * LineNumberRule
	 */
	final class LineNumberRule extends Rule {

		@Override
		public final void begin(final String name, final Attributes attrs) {
			int line = Integer.parseInt(attrs.getValue("line"));
			Label start = getLabel(attrs.getValue("start"));
			getCodeVisitor().visitLineNumber(line, start);
		}
	}

	/**
	 * LocalVarRule
	 */
	final class LocalVarRule extends Rule {

		@Override
		public final void begin(final String element, final Attributes attrs) {
			String name = attrs.getValue("name");
			String desc = attrs.getValue("desc");
			String signature = attrs.getValue("signature");
			Label start = getLabel(attrs.getValue("start"));
			Label end = getLabel(attrs.getValue("end"));
			int var = Integer.parseInt(attrs.getValue("var"));
			getCodeVisitor().visitLocalVariable(name, desc, signature, start,
					end, var);
		}
	}

	/**
	 * InvokeDynamicRule
	 */
	final class InvokeDynamicRule extends Rule {
		@Override
		public final void begin(final String element, final Attributes attrs)
				throws SAXException {
			push(attrs.getValue("name"));
			push(attrs.getValue("desc"));
			push(decodeHandle(attrs.getValue("bsm")));
			push(new ArrayList<Object>());
		}

		@Override
		public final void end(final String element) {
			ArrayList<?> bsmArgs = (ArrayList<?>) pop();
			Handle bsm = (Handle) pop();
			String desc = (String) pop();
			String name = (String) pop();
			getCodeVisitor().visitInvokeDynamicInsn(name, desc, bsm,
					bsmArgs.toArray());
		}
	}

	/**
	 * InvokeDynamicBsmArgumentsRule
	 */
	final class InvokeDynamicBsmArgumentsRule extends Rule {
		@Override
		public final void begin(final String element, final Attributes attrs)
				throws SAXException {
			ArrayList<Object> bsmArgs = (ArrayList<Object>) peek();
			bsmArgs.add(getValue(attrs.getValue("desc"), attrs.getValue("cst")));
		}
	}

	/**
	 * OpcodesRule
	 */
	final class OpcodesRule extends Rule {

		// public boolean match( String match, String element) {
		// return match.startsWith( path) && OPCODES.containsKey( element);
		// }

		@Override
		public final void begin(final String element, final Attributes attrs)
				throws SAXException {
			Opcode o = OPCODES.get(element);
			if (o == null) {
				throw new SAXException("Invalid element: " + element + " at "
						+ match);
			}

			switch (o.type) {
				case OpcodeGroup.INSN:
					getCodeVisitor().visitInsn(o.opcode);
					break;

				case OpcodeGroup.INSN_FIELD:
					getCodeVisitor().visitFieldInsn(o.opcode,
							attrs.getValue("owner"), attrs.getValue("name"),
							attrs.getValue("desc"));
					break;

				case OpcodeGroup.INSN_INT:
					getCodeVisitor().visitIntInsn(o.opcode,
							Integer.parseInt(attrs.getValue("value")));
					break;

				case OpcodeGroup.INSN_JUMP:
					getCodeVisitor().visitJumpInsn(o.opcode,
							getLabel(attrs.getValue("label")));
					break;

				case OpcodeGroup.INSN_METHOD:
					getCodeVisitor().visitMethodInsn(o.opcode,
							attrs.getValue("owner"), attrs.getValue("name"),
							attrs.getValue("desc"));
					break;

				case OpcodeGroup.INSN_TYPE:
					getCodeVisitor()
							.visitTypeInsn(o.opcode, attrs.getValue("desc"));
					break;

				case OpcodeGroup.INSN_VAR:
					getCodeVisitor().visitVarInsn(o.opcode,
							Integer.parseInt(attrs.getValue("var")));
					break;

				case OpcodeGroup.INSN_IINC:
					getCodeVisitor().visitIincInsn(
							Integer.parseInt(attrs.getValue("var")),
							Integer.parseInt(attrs.getValue("inc")));
					break;

				case OpcodeGroup.INSN_LDC:
					getCodeVisitor()
							.visitLdcInsn(
									getValue(attrs.getValue("desc"),
											attrs.getValue("cst")));
					break;

				case OpcodeGroup.INSN_MULTIANEWARRAY:
					getCodeVisitor().visitMultiANewArrayInsn(
							attrs.getValue("desc"),
							Integer.parseInt(attrs.getValue("dims")));
					break;

				default:
					throw new Error("Internal error");

			}
		}
	}

	/**
	 * MaxRule
	 */
	final class MaxRule extends Rule {

		@Override
		public final void begin(final String element, final Attributes attrs) {
			int maxStack = Integer.parseInt(attrs.getValue("maxStack"));
			int maxLocals = Integer.parseInt(attrs.getValue("maxLocals"));
			getCodeVisitor().visitMaxs(maxStack, maxLocals);
		}
	}

	final class AnnotationRule extends Rule {

		@Override
		public void begin(final String name, final Attributes attrs) {
			String desc = attrs.getValue("desc");
			boolean visible = Boolean.valueOf(attrs.getValue("visible"))
					.booleanValue();

			Object v = peek();
			if (v instanceof ClassVisitor) {
				push(((ClassVisitor) v).visitAnnotation(desc, visible));
			} else if (v instanceof FieldVisitor) {
				push(((FieldVisitor) v).visitAnnotation(desc, visible));
			} else if (v instanceof MethodVisitor) {
				push(((MethodVisitor) v).visitAnnotation(desc, visible));
			}
		}

		@Override
		public void end(final String name) {
			AnnotationVisitor av = (AnnotationVisitor) pop();
			if (av != null) {
				av.visitEnd();
			}
		}
	}

	final class AnnotationParameterRule extends Rule {

		@Override
		public void begin(final String name, final Attributes attrs) {
			int parameter = Integer.parseInt(attrs.getValue("parameter"));
			String desc = attrs.getValue("desc");
			boolean visible = Boolean.valueOf(attrs.getValue("visible"))
					.booleanValue();

			push(((MethodVisitor) peek()).visitParameterAnnotation(parameter,
					desc, visible));
		}

		@Override
		public void end(final String name) {
			AnnotationVisitor av = (AnnotationVisitor) pop();
			if (av != null) {
				av.visitEnd();
			}
		}
	}

	final class AnnotationValueRule extends Rule {

		@Override
		public void begin(final String nm, final Attributes attrs)
				throws SAXException {
			AnnotationVisitor av = (AnnotationVisitor) peek();
			if (av != null) {
				av.visit(
						attrs.getValue("name"),
						getValue(attrs.getValue("desc"),
								attrs.getValue("value")));
			}
		}
	}

	final class AnnotationValueEnumRule extends Rule {

		@Override
		public void begin(final String nm, final Attributes attrs) {
			AnnotationVisitor av = (AnnotationVisitor) peek();
			if (av != null) {
				av.visitEnum(attrs.getValue("name"), attrs.getValue("desc"),
						attrs.getValue("value"));
			}
		}
	}

	final class AnnotationValueAnnotationRule extends Rule {

		@Override
		public void begin(final String nm, final Attributes attrs) {
			AnnotationVisitor av = (AnnotationVisitor) peek();
			push(av == null ? null : av.visitAnnotation(attrs.getValue("name"),
					attrs.getValue("desc")));
		}

		@Override
		public void end(final String name) {
			AnnotationVisitor av = (AnnotationVisitor) pop();
			if (av != null) {
				av.visitEnd();
			}
		}
	}

	final class AnnotationValueArrayRule extends Rule {

		@Override
		public void begin(final String nm, final Attributes attrs) {
			AnnotationVisitor av = (AnnotationVisitor) peek();
			push(av == null ? null : av.visitArray(attrs.getValue("name")));
		}

		@Override
		public void end(final String name) {
			AnnotationVisitor av = (AnnotationVisitor) pop();
			if (av != null) {
				av.visitEnd();
			}
		}
	}

	final class AnnotationDefaultRule extends Rule {

		@Override
		public void begin(final String nm, final Attributes attrs) {
			MethodVisitor av = (MethodVisitor) peek();
			push(av == null ? null : av.visitAnnotationDefault());
		}

		@Override
		public void end(final String name) {
			AnnotationVisitor av = (AnnotationVisitor) pop();
			if (av != null) {
				av.visitEnd();
			}
		}
	}

	/**
	 * Opcode
	 */
	static final class Opcode {

		public final int opcode;

		public final int type;

		Opcode(final int opcode, final int type) {
			this.opcode = opcode;
			this.type = type;
		}
	}
}
